From: Jerry Avins on
On 4/29/2010 3:55 PM, Tauno Voipio wrote:

...

> The naming of pole count for bandpass filters may be coming from
> the design procedure where a low-pass prototype is constructed
> with the number of poles (3 for a 3 resonator filter). The low-pass
> prototype is then transferred to the center frequency by resonating
> each capacitor with an inductance and each coil with a capacitor,
> ignoring the extra poles brought in.

That makes the reason for bad terminology understandable, but leaves
open the kind of misunderstanding that sometimes sinks ships.

Jerry
--
"I view the progress of science as ... the slow erosion of the tendency
to dichotomize." --Barbara Smuts, U. Mich.
�����������������������������������������������������������������������
From: Steve Pope on
Mark <makolber(a)yahoo.com> wrote:

>the usual context where "pole" is mis-used is RF bandpass LC filters
>(not lowpass) where the term pole is misused refering to "resonator"
>or "tuned circuit" or "tank circuit".

>I agree... it is wrong.

I also ran into this "alternative" definition of a pole recently,
with respect to a passive RLC filter.

It can't be coincidence; I'm betting that is the way it
was taught to people in some archaic context.

Steve
First  |  Prev  | 
Pages: 1 2 3 4 5 6 7
Prev: Rotate 2D Gaussian
Next: signal fades in noise